• Commentary |

    Recent scientific advances make it possible to assign extreme events to human-induced climate change and historical emissions. These developments allow losses and damage associated with such events to be assigned country-level responsibility.

    • Friederike E. L. Otto
    • , Ragnhild B. Skeie
    • , Jan S. Fuglestvedt
    • , Terje Berntsen
    •  & Myles R. Allen
  • Commentary |

    In anticipation of the IPCC's Sixth Assessment Report we look back at our evolving understanding of atmospheric CH4. Though sources, sinks, and atmospheric burden are now well known, apportionment between the myriad sources and sinks, and forecasting natural emissions, remains a challenge.

    • Patrick M. Crill
    •  & Brett F. Thornton
  • Commentary |

    Ice losses from Antarctica and Greenland are the largest uncertainty in sea-level projections. Nevertheless, improvements in ice-sheet models over recent decades have led to closer agreement with satellite observations, keeping track with their increasing contribution to global sea-level rise.

    • Andrew Shepherd
    •  & Sophie Nowicki
  • Commentary |

    Since 1990, the wide range in model-based estimates of equilibrium climate warming has been attributed to disparate cloud responses to warming. However, major progress in our ability to understand, observe, and simulate clouds has led to the conclusion that global cloud feedback is likely positive.

    • Mark D. Zelinka
    • , David A. Randall
    • , Mark J. Webb
    •  & Stephen A. Klein
  • Commentary |

    The treatment of agriculture has evolved over the lifetime of the IPCC, as tracked by the assessment reports. Efforts to quantify crop yield impacts and mitigation potentials have increased significantly, as has adaptation research. However, there remains a dearth of experimental and observational studies.

    • John R. Porter
    • , Mark Howden
    •  & Pete Smith
  • Commentary |

    Solar geoengineering is no substitute for cutting emissions, but could nevertheless help reduce the atmospheric carbon burden. In the extreme, if solar geoengineering were used to hold radiative forcing constant under RCP8.5, the carbon burden may be reduced by 100 GTC, equivalent to 12–26% of twenty-first-century emissions at a cost of under US$0.5 per tCO2.

    • David W. Keith
    • , Gernot Wagner
    •  & Claire L. Zabel
  • Commentary |

    Changing climates are outpacing some components of our food systems. Risk assessments need to account for these rates of change. Assessing risk transmission mechanisms across sectors and international boundaries and coordinating policies across governments are key steps in addressing this challenge.

    • Andrew J. Challinor
    • , W. Neil Adger
    •  & Tim G. Benton
  • Commentary |

    To enable society to better manage the risks and opportunities arising from changes in climate, engagement between the users and the providers of climate information needs to be much more effective and should better link climate information with decision-making.

    • Chris D. Hewitt
    • , Roger C. Stone
    •  & Andrew B. Tait
  • Commentary |

    Policymakers are beginning to understand the scale of carbon dioxide removal that is required to keep global warming “well below 2 °C”. This understanding must now be translated into policies that give business the incentive to research, develop and deploy the required technologies.

    • Glen P. Peters
    •  & Oliver Geden
  • Commentary |

    Traditional moral arguments fail to persuade conservative climate sceptics. Pope Francis' gifting of his climate encyclical to President Trump prior to his leaving the Paris Agreement shows that even a religious leader's persuasive power is constrained by how his message resonates with conservative moral values.

    • Asheley R. Landrum
    •  & Robert B. Lull
  • Commentary |

    A giant iceberg has calved off the Larsen-C Ice Shelf, the largest remaining ice shelf on the Antarctic Peninsula, reducing its total area by ~10%. Whilst calving events are a natural phenomenon and thus not necessarily indicative of changing environmental conditions, such events can impact ice-shelf stability.

    • Anna E. Hogg
    •  & G. Hilmar Gudmundsson
  • Commentary |

    Following President Trump's withdrawal from the Paris Agreement, cities worldwide have pledged support to combat climate change. Along with a growing coalition of businesses and institutions, cities represent a beacon of hope for carbon reduction in politically tumultuous times.

    • Mark Watts
  • Commentary |

    Discriminating the climate impacts of half-degree warming increments is high on the post-Paris science agenda. Here we argue that evidence from the observational record provides useful guidance for such assessments.

    • Carl-Friedrich Schleussner
    • , Peter Pfleiderer
    •  & Erich M. Fischer
  • Commentary |

    The dramatic switch from extreme drought to severe flooding in California, and the accompanying flip from atmospheric ridge to trough in the northeastern Pacific, exemplifies the pathways to an intensified water cycle under a warming climate.

    • S.-Y. Simon Wang
    • , Jin-Ho Yoon
    • , Emily Becker
    •  & Robert Gillies
  • Commentary |

    There is no longer a choice between climate policy and no climate policy. G20 finance ministers have to play a key role in implementing smart climate policies like carbon pricing. Yet they remain reluctant to take advantage of the merits of carbon pricing for sound fiscal policy.

    • Ottmar Edenhofer
    • , Brigitte Knopf
    • , Céline Bak
    •  & Amar Bhattacharya
  • Commentary |

    Increasing demand for solution-oriented environmental assessments brings significant opportunities and challenges at the science–policy–society interface. Solution-oriented assessments should enable inclusive deliberative learning processes about policy alternatives and their practical consequences.

    • Martin Kowarsch
    • , Jason Jabbour
    • , Christian Flachsland
    • , Marcel T. J. Kok
    • , Robert Watson
    • , Peter M. Haas
    • , Jan C. Minx
    • , Joseph Alcamo
    • , Jennifer Garard
    • , Pauline Riousset
    • , László Pintér
    • , Cameron Langford
    • , Yulia Yamineva
    • , Christoph von Stechow
    • , Jessica O'Reilly
    •  & Ottmar Edenhofer
  • Commentary |

    Early-stage capital providers and clean energy technology incubators are supporting a new wave of innovations focused on end-use efficiency and demand control. This wave complements expanding investments in supply technologies required for electricity sector decarbonization.

    • A. Bumpus
    •  & S. Comello
  • Commentary |

    Continued US membership in the Paris Agreement on climate would be symbolic and have no effect on US emissions. Instead, it would reveal the weaknesses of the agreement, prevent new opportunities from emerging, and gift greater leverage to a recalcitrant administration.

    • Luke Kemp
  • Commentary |

    Decision scientists have identified remedies for various cognitive biases that distort climate-change risk perceptions. Researchers must now use the same empirical methods to identify strategies for reproducing — in the tumult of the real world — results forged in the tranquillity of their labs.

    • Dan M. Kahan
    •  & Katherine Carpenter
  • Commentary |

    In the emerging post-Paris climate governance regime, the role of scientific expertise is radically changing. The IPCC in particular may find itself in a new role, where projections of future climate function as a kind of regulatory science. This poses great challenges to conventional ideals of scientific neutrality.

    • Silke Beck
    •  & Martin Mahony
  • Commentary |

    The 4‰ initiative to sequester carbon in soils has the potential to connect sustainable development goals, enhance food security and mitigate climate change by utilizing waste organic residues.

    • A. Chabbi
    • , J. Lehmann
    • , P. Ciais
    • , H. W. Loescher
    • , M. F. Cotrufo
    • , A. Don
    • , M. SanClements
    • , L. Schipper
    • , J. Six
    • , P. Smith
    •  & C. Rumpel
  • Commentary |

    Climate change is a playground for visualization. Yet research and technological innovations in visual communication and data visualization do not account for a substantial part of the world's population: vulnerable audiences with low levels of literacy.

    • Alfons Maes
  • Commentary |

    While tackling interdependencies among food, energy, and water security is promising, three fundamental challenges to effective operationalization need addressing: the feasibility of science-policy integration, cross-scale inequalities, and path-dependencies in infrastructure and socio-institutional practices.

    • Patricia Romero-Lankao
    • , Timon McPhearson
    •  & Debra J. Davidson
  • Commentary |

    Successful projection of the distribution of surface temperature change increases our confidence in climate models. Here we evaluate projections of global warming from almost 30 years ago using the observations made during the past half century.

    • Ronald J. Stouffer
    •  & Syukuro Manabe
  • Commentary |

    President Obama's rejection of the Keystone XL pipeline in 2015 established the viability of grassroots mobilization modelled on the social movement organization Bold Nebraska. This set a precedent for communities fighting energy projects that threaten natural resources and contribute to climate change.

    • James P. Ordner
  • Commentary |

    An international coalition of museums could play a critical role in coordinating more effective public communication on and engagement with climate change.

    • Morien Rees
  • Commentary |

    Human activity is changing Earth's climate. Now that this has been acknowledged and accepted in international negotiations, climate research needs to define its next frontiers.

    • Jochem Marotzke
    • , Christian Jakob
    • , Sandrine Bony
    • , Paul A. Dirmeyer
    • , Paul A. O'Gorman
    • , Ed Hawkins
    • , Sarah Perkins-Kirkpatrick
    • , Corinne Le Quéré
    • , Sophie Nowicki
    • , Katsia Paulavets
    • , Sonia I. Seneviratne
    • , Bjorn Stevens
    •  & Matthias Tuma
  • Commentary |

    A holistic and transdisciplinary approach is urgently required to investigate the physical and socio-economic impacts of collapsing coastlines in the Arctic nearshore zone.

    • Michael Fritz
    • , Jorien E. Vonk
    •  & Hugues Lantuit
  • Commentary |

    How clouds respond to warming remains the greatest source of uncertainty in climate projections. Improved computational and observational tools can reduce this uncertainty. Here we discuss the need for research focusing on high-resolution atmosphere models and the representation of clouds and turbulence within them.

    • Tapio Schneider
    • , João Teixeira
    • , Christopher S. Bretherton
    • , Florent Brient
    • , Kyle G. Pressel
    • , Christoph Schär
    •  & A. Pier Siebesma
  • Commentary |

    Political upsets could stall coordinated international mitigation action, but emissions and investments over the next few years will have long-term consequences. Any delays to mitigation or cuts to renewable energy research by the US will likely render the 2 °C target unachievable if a global precedent is set.

    • Benjamin M. Sanderson
    •  & Reto Knutti
  • Commentary |

    An end-to-end comprehensive climate information system is needed to complement mitigation and adaptation as responses to the threat of human-induced climate change.

    • Kevin E. Trenberth
    • , Melinda Marquis
    •  & Stephen Zebiak
  • Commentary |

    Cities are becoming increasingly important in combatting climate change, but their overall role in global solution pathways remains unclear. Here we suggest structuring urban climate solutions along the use of existing and newly built infrastructures, providing estimates of the mitigation potential.

    • Felix Creutzig
    • , Peter Agoston
    • , Jan C. Minx
    • , Josep G. Canadell
    • , Robbie M. Andrew
    • , Corinne Le Quéré
    • , Glen P. Peters
    • , Ayyoob Sharifi
    • , Yoshiki Yamagata
    •  & Shobhakar Dhakal
  • Commentary |

    To catalyse climate transformation, we need leadership everywhere. It is time for more of us to take the first steps to lead actively.

    • Thomas S. Bateman
    •  & Michael E. Mann
  • Commentary |

    Avoiding losses from climate change requires socially engaged research that explains what people value highly, how climate change imperils these phenomena, and strategies for embracing and managing grief.

    • Jon Barnett
    • , Petra Tschakert
    • , Lesley Head
    •  & W. Neil Adger
  • Commentary |

    Earth's surface gained 115,000 km2 of water and 173,000 km2 of land over the past 30 years, including 20,135 km2 of water and 33,700 km2 of land in coastal areas. Here, we analyse the gains and losses through the Deltares Aqua Monitor — an open tool that detects land and water changes around the globe.

    • Gennadii Donchyts
    • , Fedor Baart
    • , Hessel Winsemius
    • , Noel Gorelick
    • , Jaap Kwadijk
    •  & Nick van de Giesen
  • Commentary |

    Understanding how the overall risks of extreme events are changing in a warming world requires both a thermodynamic perspective and an understanding of changes in the atmospheric circulation.

    • Friederike E. L. Otto
    • , Geert Jan van Oldenborgh
    • , Jonathan Eden
    • , Peter A. Stott
    • , David J. Karoly
    •  & Myles R. Allen
  • Commentary |

    The impacts of climate change imply a reconceptualization of environment-related criminality. Criminology can offer insight into the definitions and dynamics of this behaviour, and outline potential areas of redress.

    • Rob White
  • Commentary |

    The success of the Paris Agreement relies on a system of 'pledge and review', and the power of shaming laggards. This puts much of the burden for holding countries accountable on civil society.

    • Jennifer Jacquet
    •  & Dale Jamieson
  • Commentary |

    Indonesian peatlands need to be protected and restored to prevent fires and the health, environmental and economic impact that they have on the wider region.

    • Luca Tacconi
  • Commentary |

    The Paris Agreement duly reflects the latest scientific understanding of systemic global warming risks. Limiting the anthropogenic temperature anomaly to 1.5–2 °C is possible, yet requires transformational change across the board of modernity.

    • Hans Joachim Schellnhuber
    • , Stefan Rahmstorf
    •  & Ricarda Winkelmann
  • Commentary |

    The recent El Niño event has elevated the rise in CO2 concentration this year. Here, using emissions, sea surface temperature data and a climate model, we forecast that the CO2 concentration at Mauna Loa will for the first time remain above 400 ppm all year, and hence for our lifetimes.

    • Richard A. Betts
    • , Chris D. Jones
    • , Jeff R. Knight
    • , Ralph F. Keeling
    •  & John J. Kennedy
  • Commentary |

    The academic community could make rapid progress on quantifying the impacts of limiting global warming to 1.5 °C, but a refocusing of research priorities is needed in order to provide reliable advice.

    • Daniel Mitchell
    • , Rachel James
    • , Piers M. Forster
    • , Richard A. Betts
    • , Hideo Shiogama
    •  & Myles Allen
  • Commentary |

    In the aftermath of COP21, potential post-2030 emission trajectories and their consistency with the 2 °C target are a core concern for the ocean scientific community in light of the end-century risks of impact scenarios.

    • Alexandre K. Magnan
    • , Michel Colombier
    • , Raphaël Billé
    • , Fortunat Joos
    • , Ove Hoegh-Guldberg
    • , Hans-Otto Pörtner
    • , Henri Waisman
    • , Thomas Spencer
    •  & Jean-Pierre Gattuso
  • Commentary |

    The value of the social sciences to climate change research is well recognized, but notable gaps remain in the literature on adaptation in agriculture. Contributions focus on farmer behaviour, with important research regarding gender, social networks and institutions remaining under-represented.

    • Debra Davidson
  • Commentary |

    Insurance is gaining importance in and beyond the climate negotiations and offers many opportunities to improve climate risk management in developing countries. However, some caution is needed, if current momentum is to lead to genuine progress in making the most vulnerable more resilient to climate change.

    • Swenja Surminski
    • , Laurens M. Bouwer
    •  & Joanne Linnerooth-Bayer
  • Commentary |

    It has been claimed that the early-2000s global warming slowdown or hiatus, characterized by a reduced rate of global surface warming, has been overstated, lacks sound scientific basis, or is unsupported by observations. The evidence presented here contradicts these claims.

    • John C. Fyfe
    • , Gerald A. Meehl
    • , Matthew H. England
    • , Michael E. Mann
    • , Benjamin D. Santer
    • , Gregory M. Flato
    • , Ed Hawkins
    • , Nathan P. Gillett
    • , Shang-Ping Xie
    • , Yu Kosaka
    •  & Neil C. Swart
  • Commentary |

    Insights about climate are being uncovered thanks to improved capacities to observe ocean salinity, an essential climate variable. However, cracks are beginning to appear in the ocean observing system that require prompt attention if we are to maintain the existing, hard-won capacity into the near future.

    • Paul J. Durack
    • , Tong Lee
    • , Nadya T. Vinogradova
    •  & Detlef Stammer
  • Commentary |

    The Paris Agreement contains an ambition to limit global warming to no more than 1.5 °C above pre-industrial levels, changing the context for policy-relevant research and extending a challenge to the IPCC and researchers.

    • Mike Hulme